Well, I was originally Anti-ban for quite a while, that was until Crow posted his graph and DMG pointed out the rules we put down just for MK, everyone else has planking that is a lot easier to stop, even Falco who supposidly gets destroyed by planking can do something.
I learned from helping in a project to test how broken planking was that MK's planking was superior to everyone elses by a mile.
It was mostly how Dark.pch gave frame data on MK's planking. He posted data to show Peach could stop everyone's planking, except MKs, quite easily. The problem with MK was the fact he proved with frame data that MK was only vulnerable for 3 frames while planking. So you need a move that comes out at that speed or faster that also has more range than MK's Uair. There are some characters that have moves almost fast enough to get a planking MK, Lucario, Snake, Wario, Marth, or ones that had moves fast enough but lacked range, Falco, Peach, Squirtle, Zero Suit Samus.
So MK has to make a mistake for anyone to punish him. It was really stupid since something like this can turn the game into MK vs MK. At least with everyone elses planking people have answers, MK's however has none.
With the bracket idea it could work, but I do agree a lot of people are going to pick the MK-less scene more often than not. People would prefer if MK was banned, even I think the game would be better without him, even if it was unfair to MK mains.
I'm not going to advocate a ban to people, only because I'd rather not start a fight or something when the BBR is debating this and deciding if MK is truly bannable, granted DMG is working on a huge post to show that a Planking MK unbeatable unless he makes a mistake and how most of the cast is at a disadvantage if people are looking at frame data and hitboxes. You can powershield his Uair and have ways to punish, Falco for example can PS buffer a dash and get a bair off, but that's trying to predict a 2 frame move while human reaction time is only 8 frames at best.
It's kinda like how I LOL'd at people who said Lucario vs MK was 50:50. Lucario has nothing on the ground that outranges his moves except Fsmash. Even then most of Lucario's ranged moves are too slow to comes out so MK has time to do other things, like get read to powershield Fsmash and dash grab Lucario out of it. The only reason it's not terrible for Lucario is because his air moves can compete with MK's, a projectile that kills, and Lucario kill MK because, "Your only making me stronger."
That's why it's only a 4:6, but in the grand scheme of things most of the cast is still beaten very badly by MK, even worse than this. Then if people actually thought if planking was involved it only gets worse. So I do support a ban, but I don't want to advocate it too much since I want to just play the game more than I want to try and ban a character.
edit: Wow I really ranted on about this, LOL.